hot/cold water surges

Tweitekamp

Active Member
Just wondering if someone could give me a clue what to look for. But when we take showers, it surges hot/cold water whenever the pump turns on. Hot, cold, hot, cold, hot, cold......which is really tough to deal with while bathing 1 and 3 year old kids. It gets real cold when you are trying to balance out really hot water!

What could be causing this hot cold surge? It really doesn't seem to get much better the longer the water is run. It does get slightly better, but our old junk campers worked flawlessly. they would pulse once or twice and then it was mixed to the proper temperature. I don't know if it has anything to do with where the pump is located (front 1/3 of trailer) vs. where the tank (over axles I believe) is located. I sure wouldn't think that would be the case.

I really want to get an accumulator to plumb inline. I hear that will help, but I still don't think that I should have this issue during the whole time in the shower.

Any thoughts would be greatly appreciated!

Todd
 

Garypowell

Well-known member
The pump turn on is pressure activated....and unfortunately deactivated too. I am sure there are too many variables to figure out where the actual problem is (your surges) or if the fault of one component. You have already mentioned tank vs. pump location...but you now have a different pump, more lines, etc, etc, etc. Not to mention that there is different pressure switch than you had before. Since I don't dry camp and use the pump (only at rest stops) I really don't know about surge tanks but if Jnbhobe says it works.....I'd take his word for it. And I think he'd probably tell you how to do it too.
 

danemayer

Well-known member
when we take showers, it surges hot/cold water whenever the pump turns on. Hot, cold, hot, cold, hot, cold
Hi Tweitekamp,

Can you clarify your description?

Is the pump making noise as though it's starting and stopping frequently while using the shower or does the noise continue for the entire shower?

Does the volume of water coming out of the shower change from high flow to low flow? If yes, does the water get cold momentarily when the flow goes back to high flow?

Does the water flow stay the same, but temperature changes from hot to cold?
 

cookie

Administrator
Staff member
A couple of questions.
While showering, is anyone washing dishes, brushing teeth or flushing the toilet?
Do you have an outside shower and are both valves turned off?
If you have a water heater bypass, is it in the normal use position?
These are all things that could cause problems.

Peace
Dave

Sent from my DROID RAZR using Tapatalk 4
 
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Tweitekamp

Active Member
I think the pump is cycling normally. Probably 2 seconds on and 2-5 off. I don't think it is any worse than my previous two campers. It just pumps scalding hot water then freezing cold water. You can back off the hot water then you have some really cold water coming out. I do have a outside shower that is probably on the same circuit. I had questions about the shower originally but one of the last times we were out I made sure to turn the head ON and make sure no water came out the head when I shut the hot and cold knobs off. I think it is right. Honestly I would like to get rid of the shower but there is hardly any room to put proper shut off valves in the area. Less water faucets the better in my opinion!!!

Basically it is cycling in a manner I feel is pretty normal. It is hot when the pump running and cold when not running. Also...it has poor pressure at the shower. The other sinks seem normal for a RV.

Hope this has given some more helpful info!!
 

Tweitekamp

Active Member
Gary, I have not modified anything on this sundance. I have put water in it and that's it. I have thought about a accumulator on it and ultimately will. I just hear those help if the pump is located a distance from the tank. But I just wanted to clarify that I have not touched anything on this unit.
 

Tweitekamp

Active Member
Danemayer, the water flow does change when the pump turns on and when it turns off. It doesn't change near as much on the other faucets as it does the shower.

Pump does not run the entire time. It cycles as it should. When pressure builds and drops it turns on and off

thanks!!
 

danemayer

Well-known member
When running the shower off the pump, our pump runs continuously. While the shower is on, there's no pressure buildup at the pump output side of the pump, so the pump stays on. The fact that yours is cycling on and off suggests that something is building up pressure on the output side which the pump interprets as a closed shower faucet, so it stops pumping.

The uneven hot/cold suggests that one of the lines has a restriction. Because you get a surge of cold water when the pump stops, I would guess that the cold water line has the restriction and is building pressure that causes the pump to stop. When the pump stops, the hot water stops. The built up pressure on the cold side causes the surge of cold water. When the built-up pressure is relieved, the pump interprets that as an open faucet and starts again, allowing hot water to flow again.

I've attached a drawing taken from page 6 of our Water Systems Guide. The yellow oval shows the area where I suspect you may find a kink or other restriction. The drawing is generic, but is representative of the plumbing most of us have.
 

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  • Water System w lines 1 restriction.pdf
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dbbls59

Well-known member
Todd, I had the same problem with my previous SOB trailer. I don't remember the brand of water pump, Surflo I think, but there was a screw on the head of the pump. I turned it and stopped the pulsing and solved the hot cold cycling. I don't remember which way I turned it either, too long ago. I know my Big Country does not have the brand of pump that was in my SOB so I doubt if your Sundance dues either, but you might check this. Otherwise I think a accumulator tank will solve your problem.
 

Tweitekamp

Active Member
Dan, When we are doing a constant flow the pump will continuously flow because the pressure is always lower. Granted, we are almost never hooked to city water. We have to conserve so we are turning the water on and off all the time. We get the on/off scenario for a short while along with the hot/cold blasts. That lasts quite a while THEN when we are somewhat close to getting a REASONABLE temperature swing we have to shut the water off again.

Maybe I am just going to have to put a accumulator on it and deal with it. There really isn't any way of changing what we are doing because of water usage. I am just trying to make it more bearable for the kids. We use the showerhouse 90% of the time.

Thanks for your help. I will save the document you pasted and read it tonight.
 

123camper

Well-known member
Once you have your temp adjusted use the button on the shower head to turn your flow off while washing. Doing this will keep the pressure even on the cold and hot water lines. The flow will be min. And the pump will cycle until you turn it on for rinsing keeping the pressures equal.
 

Tweitekamp

Active Member
Yeah, already do that.

Gonna purchase a accumulator kit and pray. Just wanted to figure it out so it is easier on the kids.

thanks for the posts guys

todd
 

Tweitekamp

Active Member
Just wanted to post that I just finished installing a accumulator and silencing kit. Awesome!! I also adjusted the pressure of the pump by one turn of the screw. Very quiet and very pleased. Will see if the shower works any better this weekend. I'll keep you posted, but I think it is a great improvement and everyone should do it!!
 

Tweitekamp

Active Member
No I don't but I can take some this weekend. Let's make sure it works for a weekend. Hate to take pictures if I need modify it!! I'll take some pictures an somehow figure out how to post them
im pretty stoked though!
 

Tweitekamp

Active Member
57, I got it from Tweety's. I had a gift certificate from christmas that I hadn't spent. I meant to do it this summer but didn't. You can get accumulators anywhere on the ol' interweb. I bought a surflo just to match my pump. I also got a silencing kit which was 12 bucks or so. Just 2 long hoses. I think you could make one cheaper than the kit. If I would have studied my space before I bought the kit I would have bought hose from the hardware store and fittings online. I think buying 90's with barb fittings is easier to deal with than straights in tight areas. Plus the silencing kit hoses are about 16" long which is a lot of hose in a small area such as mine. If you have room, maybe this would be a very simple way to go. Our RV dealership is going out of business so I bought a bunch of fittings for the future.

I haven't snapped any pictures but I just secured the accumulator to the wall and put it after the pump like the instructions said to do. Pump feeds the accumulator and the accumulator feeds the house. simple and it should be installed from the factor in my opinion. So cheap and so nice!
 
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